Henry c



' (No Model.)

H. c. SERGEANT.

ROCK DRILL.

No. 349,409. Patented Sept. g1, 1886.

UNITED. STATES "PATENT OFFICE.

HENRY O. SERGEA'NT, OF NEXV YORK, N. Y.

ROCK-DRILL.

SPECIFICATION forming part of Letters Patent 110,349,409, datedSeptember 21, 1886.

Application filed January 2, 1886. Serial No. 187,402.

To all whom it may concern:

Be it known that I, HENRY O. SERGEANT, of New York, in the county of NewYork and State of New York, have invented a new and useful Improvementin Rock-Drills, of which the following is a specification.

In rock-drills as heretofore constructed it has been common to providean india-rubber buffer or cushion, which will serve to diminish theshock in case of the piston striking vat the end of the cylinder, andwill prevent the piston from knocking out or breaking the cylinder-head.

It is well known that india-rubber, although it may be readilycompressed in one direction, requires room for expansion in anotherdirection, and hence if a disk of india-rubber be compressed by a boltupon its face it will expand laterally or radially so as to enlarge itsdiameter, and may burst the part which surrounds it and keeps it inplace.

The object of my invention is to enable the buffer-case, or that partwhichhas the bufl'er inclosed within it, to be made separate from andindependent of the cylinder and its lower end, so that if broken it maybe renewed at a very much less cost than renewing the whole cylinder orits lower head, and so that it may be made of a metal stronger thancast-iron and less likely to be broken than the cylinder or head.

The invention consists in the combination with the cylinder, its lowerhead, and thepiston of .a rock-drill, of an india-rubber buffer orcushion to check the motion of the piston, and a casing or framesurrounding the buffer and made separate from the cylinder and its lowerhead and serving to sustain the strain produced by the lateral expansionof the buffer.

The invention also consists in the combination, with a cylinder, piston,and lower head of a rock-drill, of an india-rubber buffer to der andhead are both preferably provided with cylindric or circular projectionsat their (No model.)

adjacent ends, and the band or collar which is interposed between thehead and cylinder is fitted to such circular projections, the cylinder,head, and band or collar all being secured together by means of theordinary side bolts, which are provided in the drill.

In the accompanying drawings, Figure 1 is a longitudinal section of suchportions of a drill as are necessary to illustrate my invention. Fig. 2is a plan of the lower portion of the cylinder and the lower head, andFig. 3 is a face view of the band or collar which is interposed betweenthe head and cylinder.

Similar letters of reference designate corresponding parts in all thefigures.

A designates the cylinder of a rock-drill, which may be of any suitableconstruction; and B designates a piston, from which extends apiston-rod,B, with which the drill-rod is to be connected.

0 designates an india-rubber buffer or cushion, which surrounds thepiston-rod B, andwhich receives the impact of the piston in case itfails to change in the direction of its movement by the action of thevalve of the drill, or by striking the rock.

In order to avoid the bursting of the drillcylinder or its lower head bythe expansion of the rubber buffer or cushion, I arrange the latterbeyond the end'of the cylinder, and I sustain the strain produced by thelateral expansion of the buffer or cushion bya casing or frame which isseparate from and independent of the cylinder and lower head, and whichmay be renewed at a very much less expense than the cylinder or itshead. I prefer to make this casing or frame D for the buffer in the formof a-band or collar, which is interposed between the lower head, E, andthe end of the cylinder, as shown in Figs. 1 and 2.

. By making the casing or frame in the form of a band or collar, whichis made separate from both the lower head and the cylinder, I not onlymake it in a piece which may be renewed independently of the cylinder,but I am also able to make it of forged steel oriron, or of any othermetal, which will be far stronger than the cast-iron of which thecylinder is most advantageously made. i

The lower head, E, and the stuffing-box gland F, which is fittedthereto, are both represented as made in halves or divided axially, sothat they may be readily applied to the piston-rod, having an integralpiston at one end and at the other end an enlargement forming a chuck toreceive the drill-rod.

In order to support the buffer or cushion I employ a divided ring, G,which surrounds the piston-rod B, and enters slightly into the cylinderA, the ring being provided with a flange, g, which bears against the endof the cylinder, and the buffer or cushion O is arranged between thering G' and the lower head, E.

As shown in Fig. 1, the cylinder A and lower head, E, are formed withcylindric or eireular projections a e, and the band or collar D isfitted upon these projections, and by this means I am enabled to employa buffer or cushion, O, of larger area than would be possible if it werearranged within the cylinder.

The band or collar D is provided, at diametrically-opposite points withlugs or ears (I, which receive the side bolts, H, whereby the heads ofthe cylinder are secured in place, and when the nuts upon these boltsare tightened it will be understood that the band or collar D is heldtight-1y between the lower head, E, and the cylinder.

WVhat I claim as my invention,and desire to secure by Letters Patent,is-

1. The combination, with the cylinder, its lower head, and the piston ofa rock-drill, of an india-rubber buffer, and a casing or framesurrounding the buffer and made separate from the cylinder and itslower-head, substantially as herein described.

2; The combination, with the cylinder, piston, and lower head ofa'roek-drill, of an india-rubber bufi'er, and a casing or frameconsisting of a collar or band, D, having a plain cylindrie interiorsurrounding the buffer and interposed between and made separate from thecylinder and head, substantially as herein described. y

3. The combination, with the cylinder and head of a rock-drill, bothprovided with cylindric or circular projections at their adjacent ends,of an india-rnbber buffer between the cylinder and head, and a band orcollar interposed between and made separate from the cyl inder and head,and fitted to said circular projections, the said band or collar servingto sustain the strain produced by lateral expansion of the buffer,substantially as herein described.

O. HALL, FREDK. HAYNES.

